Method for processing a porous article

Abstract

A method of processing a porous article includes distributing a blended material that includes an electrically conductive material and a binder into a cavity of a mold that is at a temperature below a curing temperature of the binder. The electrically conductive material is formed from particles of the electrically conductive material that have a size distribution such that 10 vol % of the particles are less than 12 micrometers in diameter, 50 vol % of the particles are less than 27 micrometers in diameter, and 90 vol % of the particles are less than 53 micrometers. The blended material is compressed within the cavity under a molding pressure, and the mold is heated to a curing temperature of the binder to form a molded article.

What is claimed is: 
     
       1. A method of processing a porous article, the method comprising:
 distributing a blended material including an electrically conductive material and a binder into a cavity of a mold that is at a temperature below a curing temperature of the binder, where the electrically conductive material is formed from particles of the electrically conductive material that have a size distribution such that 10 vol % of the particles are less than 12 micrometers in diameter, 50 vol % of the particles are less than 27 micrometers in diameter, and 90 vol % of the particles are less than 53 micrometers; 
 compressing the blended material within the cavity under a molding pressure; 
 while the blended material is under compression in the cavity, heating the mold from a cool temperature to the curing temperature to thereby form a molded article; and 
 carbonizing the binder of the molded article to form the porous article. 
 
     
     
       2. The method as recited in  claim 1 , further including carbonizing in an inert atmosphere. 
     
     
       3. The method as recited in  claim 1 , further including:
 forming the blended material to include agglomerates having the electrically conductive material attached with the binder. 
 
     
     
       4. The method as recited in  claim 3 , further including:
 comminuting the agglomerates to form smaller agglomerates. 
 
     
     
       5. The method as recited in  claim 4 , further including:
 classifying the smaller agglomerates such that the blended material includes an average diametric size within a range of 50-600 micrometers. 
 
     
     
       6. The method as recited in  claim 4 , further including:
 adding additional binder to the smaller agglomerates. 
 
     
     
       7. The method as recited in  claim 1 , wherein the particles of the electrically conductive material have a size distribution such that 10 vol % of the particles are less than 12 micrometers in diameter, 50 vol % of the particles are less than 17 micrometers in diameter, and 90 vol % of the particles are less than 25 micrometers. 
     
     
       8. The method as recited in  claim 1 , further including, prior to distributing the blended material:
 forming the blended material to include a dry mix of particles of the electrically conductive material and particles of the binder. 
 
     
     
       9. The method as recited in  claim 1 , further including, prior to distributing the blended material:
 wet mixing particles of the electrically conductively material and particles of the resin binder with a liquid carrier to form a slurry, casting the slurry into a solid shape, and comminuting the solid shape to form the blended material. 
 
     
     
       10. The method as recited in  claim 1 , further including, prior to distributing the blended material:
 heating particles of the electrically conductive material and particles of the binder, mixing the heated particles together to form an agglomerate of the electrically conductive material attached with the binder, and forming smaller agglomerates from the agglomerate as the blended material. 
 
     
     
       11. The method as recited in  claim 1 , further including, prior to distributing the blended material:
 wet mixing particles of the electrically conductive material and particles of the binder with a liquid carrier to form a slurry, and drying the slurry under agitation conditions to form the blended material. 
 
     
     
       12. The method as recited in  claim 1 , further including, prior to distributing the blended material:
 forming the blended material with a composition that includes 65-90 wt % of the electrically conductive material and a remainder of the binder. 
 
     
     
       13. The method as recited in  claim 1 , wherein the carbonizing includes heating the molded article in an inert atmosphere to thermally decompose the binder. 
     
     
       14. The method as recited in  claim 1 , further including:
 applying a hydrophilic material to the porous article. 
 
     
     
       15. The method as recited in  claim 1 , wherein distributing the blended material includes leveling a charge of the blended material in the cavity of the mold. 
     
     
       16. The method as recited in  claim 1 , wherein the blended material consists of the electrically conductive material and the binder. 
     
     
       17. The method as recited in  claim 1 , wherein the porous article is a porous water transport plate for a fuel cell. 
     
     
       18. The method as recited in  claim 17 , wherein the porous water transport plate has an average pore size of about 1-3 micrometers. 
     
     
       19. The method as recited in  claim 1 , wherein the compressing of the blended material within the cavity under the molding pressure includes:
 compressing under a first pressure of 0.5-100 pounds per square inch (3.5-689 kilopascals) at a first temperature of 10-50° C.; and 
 followed by compressing under a second pressure of 400-800 pounds per square inch (2758-5516 kilopascals) as the mold is raised to a second temperature of 130-200° C.